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User's Guide
SNVA457B–March 2011–Revised April 2013
AN-2085 LMZ23605/03, LMZ22005/03 Evaluation Board
1 Introduction
The LMZ23605/03, LMZ22005/03 evaluation boards are designed to be an easy-to-use platform to
evaluate the full capabilities of this family of SIMPLE SWITCHER® power modules. The PCB construction
has excellent thermal performance and includes extra locations for optional components that may not be
required in the end application.
The LMZ23605/03 can accept an input voltage rail between 6V and 36V and the LMZ22005/03 can accept
an input voltage rail between 6V and 20V. The devices can deliver an adjustable and highly accurate
output voltage as low as 0.8V and as high as 6V. The control architecture is constant frequency PWM with
emulated current mode sensing. The control loop operates well with low ESR output capacitors such as
ceramics or specialty polymer. The precision enable input allows for programmable UVLO on the input
supply or flexibility in sequencing. The external soft-start capacitor facilitates controlled output rise time at
startup. The module family is a reliable and robust solution with cycle-by-cycle valley current limit to
protect for over current or short-circuit faults. Additionally there is thermal shutdown protection, and they
will start up into a pre-biased output. The free-running switching frequency is 812 kHz (typ) and a 650 kHz
to 950 kHz synchronization range is supported.
2 Board Specifications
• V
IN
= 6V to 36V (LMZ22005/03 limited to 20V)
• Enable UVLO = 5.7V
• V
OUT
= 3.3V
• I
OUT
= 0 to 5A (LMZ23603 and LMZ22003 limited to 3A)
• θ
JA
= 12°C / W, θ
JC
= 1.9°C/W
• PCB designed on four layers; Inner are 2 oz; Outer are 3 oz.
• Measures 3.5 in. x 3.5 in. (8.9 cm x 8.9 cm) and is 62mil (.062”) thick of FR4 laminate material
• Max ambient temp of 70°C at full 5A load (12 Vin)
For additional circuit considerations refer to the Applications Section of the LMZ23605/03 or LMZ22005/03
data sheets. For negative output voltage connections follow the method shown in AN-2027.
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SNVA457B–March 2011–Revised April 2013 AN-2085 LMZ23605/03, LMZ22005/03 Evaluation Board
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